﻿<p>A space represents an area or volume bounded actually or theoretically. Spaces are areas or volumes that provide for certain functions within a building.</p>
<p>A space is associated to a building storey (or in case of exterior spaces to a site). A space may span over several connected spaces. Therefore a space group provides for a collection of spaces included in a storey. A space can also be decomposed in parts, where each part defines a partial space. This is defined by the <em>CompositionType</em> attribute of the supertype <em>IfcSpatialStructureElement</em> which is interpreted as
follow:</p>
<ul>
<li>COMPLEX = space group</li>
<li>ELEMENT = space</li>
<li>PARTIAL = partial space</li>
</ul>
<blockquote class="note">
NOTE&nbsp; View definitions and implementation agreements may restrict spaces with <em>CompositionType</em>=ELEMENT to be non-overlapping.</blockquote>
<p>The <em>IfcSpace</em> is used to build the spatial structure of a
building (that serves as the primary project breakdown and is
required to be hierarchical). The spatial structure elements are
linked together by using the objectified relationship
<em>IfcRelAggregates</em>.</p>
<p>Figure 3 shows the <em>IfcSpace</em> as part of the spatial structure. It also serves as the spatial container for space related elements.</p>

<blockquote class="note">NOTE&nbsp; Detailed requirements on mandatory element containment and placement structure relationships are given in view definitions and implementer agreements.</blockquote>



<table summary="spatial structure" cellpadding="2" cellspacing="2">

<tr><td align="left" valign="top"><img src="../../../figures/ifcspace-spatialstructure.png" alt="spatial structure" border="0" height="350" width="800"></td></tr>

<tr><td><p class="figure">Figure 3 &mdash; Space composition</p></td></tr>

</table>



<p>The following guidelines should apply for using the <em>Name</em>, <em>Description</em>, <em>LongName</em> and <em>ObjectType</em> attributes.</p>
<ul>
<li><em>Name</em> holds the unique name (or space number) from the plan.</li>
<li><em>Description</em> holds any additional information field the user may have specified, there are no further recommendations.</li>
<li><em>LongName</em> holds the full name of the space, it is often used in addition to the <em>Name</em>, if a number is assigned to the room, then the descriptive name is exchanged as <em>LongName</em>.</li>
<li><em>ObjectType</em> holds the space type, i.e. usually the functional category of the space .</li>
</ul>
<blockquote class="note">NOTE&nbsp; In cases of inconsistency between the geometric representation of the <em>IfcSpace</em> and the combined geometric representations of the surrounding <em>IfcRelSpaceBoundary</em>, the geometric representation of the space should take priority over the geometric representation of the surrounding space boundaries.</blockquote>

<p>Figure 4 describes the heights and elevations of the <em>IfcSpace</em>.</p>
<ul>
 <li>elevation of the space (top of construction slab) equals elevation of storey: provided by <em>IfcBuildingStorey.Elevation</em> relative to em>IfcBuilding.ElevationOfRefHeight</em></li>
<li>elevation of the space flooring (top of flooring on top of slab): provided by <em>IfcSpace.ElevationWithFlooring</em> relative to <em>IfcBuilding.ElevationOfRefHeight</em></li>
<li>height of space (top of slab below to bottom of slab above): provided by BaseQuantity with Name="Height"</li>
<li>floor height of space (top of slab below to top of flooring): provided by BaseQuantity with Name="FinishFloorHeight"</li>
<li>net height of space (top of flooring to bottom of suspended ceiling): provided by BaseQuantity with Name="FinishCeilingHeight"</li>
</ul>

<table summary="attributes" cellpadding="2" cellspacing="2">
<tr><td align="left" valign="top"><img src="../../../figures/ifcspace_heights.png" alt="space heights" border="0"
height="400" width="450"></td></tr>
<tr><td><p class="figure">Figure 4 &mdash; Space elevations</p></td></tr>
</table>

<blockquote class="history">
HISTORY&nbsp; New entity in IFC1.0
</blockquote>
